Thin films of cadmium stannate were prepared using thermal chemical spray pyrols: Cadmium stannate' solution (0.2M) was prepared by dissolution of CdCl25H2O in C2H5OH tion of SnCl23H2O in CH3COOH at molar 2:1, respectively. The Cd2Sn04 solution was spra substrate that was kept at 300°C. The studies of structure showed that the prepared thin film phous. After annealing, no changes observed in the films' structure. The type of electronic t determined by studying the Ultra Violet/Visible (UV/Vis) spectrum. Energy's gap, width of lo tail, refraction coefficient, reflection index, and extinction coefficient were calculated bef annealing. The optical constants were increased by increasing annealing's temperature and ness.